Unable to get i2c30 working on pins P03 and P04

RE: Unable to get i2c30 working on pins P03 and P04

Ressa — Tue, 27 Jan 2026 12:59:39 GMT

Hi Simon,

In the datasheet of nRF54L15, there are some more details about the pin configuration for specific conditions when using TWI, please have a look at them: TWIM — I2C compatible two-wire interface controller with EasyDMA
Also just wondering if you can try S0D1 as well.

RE: Unable to get i2c30 working on pins P03 and P04

SimonV — Mon, 26 Jan 2026 12:16:18 GMT

Hello!

Can i just ask do you know what is the reason that we needed to enable drive mode on these pins. What ended up working for me was

nordic,drive-mode = <NRF_DRIVE_S0H1>;

Is anything about these pins on port 0 special?

RE: Unable to get i2c30 working on pins P03 and P04

SimonV — Wed, 21 Jan 2026 09:54:09 GMT

Thank you that was it!!!

RE: Unable to get i2c30 working on pins P03 and P04

Ressa — Tue, 20 Jan 2026 14:17:49 GMT

Only thing I added is to increase IO drive level:

RE: Unable to get i2c30 working on pins P03 and P04

Ressa — Tue, 20 Jan 2026 14:10:53 GMT

Hi Simon,

Thanks for the report.
Just wondering if the issue is still there?
I tried your code on nRF54L15 DK , and set SCL on P0.4 and SDA on P0.0 and it seems fine:

RE: Unable to get i2c30 working on pins P03 and P04

SimonV — Fri, 16 Jan 2026 13:14:57 GMT

On our pcb i can not do it unfortunately. However i did some tests on our nrf54l15 dev kit and i have compiled the results into this pdf. this were the results:

IF i use P00 for SDA:

SDA is always high and clock is not consistent:

If I use P01 for SDA:

SDA is producing some noise and clock disappears

if i use P02 for SDA:

SDA is always held high

if i use P03: SDA is just noise and its held low:

SCL was always on P04

I also tried putting SCL to P03 and SDA to P02

SDA is again held low and it has random noise but it almost looks like a signal

devzone.nordicsemi.com/.../nrf54l15-i2c-results.pdf

RE: Unable to get i2c30 working on pins P03 and P04

Ressa — Fri, 16 Jan 2026 11:07:48 GMT

Just as a quick check, can you try to move SDA line to other P0 port pins (if possible on hardware) ? while keeping the same pin for SCL. Would be interesting to see if the other pins showing same behavior nr not or it is only P0.03.

RE: Unable to get i2c30 working on pins P03 and P04

SimonV — Fri, 16 Jan 2026 10:17:09 GMT

That was a mistake on my part. I accidentally uploaded the version where i had them disabled they should be and are enabled. I tried with them enabled and disabled and i got the same results

RE: Unable to get i2c30 working on pins P03 and P04

Ressa — Fri, 16 Jan 2026 10:15:23 GMT

Hi Simon,

Do you have external pull up on the pins? the internal ones are disabled explicitly. If you don't have external ones try to use internal pull up to see if it helps:

change "bias-disable;" to "bias-pull-up;"

RE: Unable to get i2c30 working on pins P03 and P04

SimonV — Fri, 16 Jan 2026 07:34:14 GMT

I saw that i uploaded the wrong image... I have swapped the pins in the software as you suggested but i get the same response as when i was doing it "normally." (the picture has sda and scl swapped). For some reason the SDA signal is not cycling correctly for me.

RE: Unable to get i2c30 working on pins P03 and P04

embedded0411 — Thu, 15 Jan 2026 19:48:28 GMT

Try swapping pin numbers in your overlay and keep your I2C wiring the same.

psels = <NRF_PSEL(TWIM_SCL, 0, 3)>,

<NRF_PSEL(TWIM_SDA, 0, 4)>;

I had this weird bug where all my I2C SDA connections were physically connected to pin 9 on an eval board and wouldn't work unless I defined that pin as my clock and my clock line as data. Its either an inverted mapping in Zephyrs bindings, an NFC pin quirk, or a bug with Nordic's nrfx driver.